8 Repeated sequences at the end of linear chromosomes (TTAGGG in humans)Protects against environmental damage, recombination with other chromosomes, & from loss of information during replicationForms a guanine-quadraduplex

10 The Eukaryotic Problem of Telomere ReplicationRNA primer near end of the chromosome on lagging strand can’t be replaced with DNA since DNA polymerase must add to a primer sequence.Do chromosomes get shorter with each replication?

18 The role of senescence : a limit to proliferationSuggested purpose :to limit the proliferative capacity of normal cells-> a mechanism involved in normal development& tissue maintenance-> a potent tumor-protection mechanism-> must be prevented in proliferative cell compartments(stem cells)